when you reinstalled inv 11 and vault and content centre, did you choose IIS or AWS? perhaps you chose a different option upon your new install than your previous install? (a: please read at bottom of this post for more information on that).
The content center, in recent version requires the adms to be utilised so to answer your question, that is why the vault is needed, even if you are not using vault for your projects.
on a previous occasion i had a problem with my cc and vault login. this was due to a corruption of my database (microsoft sql resources). no matter what i did i could not get vault to work again. (b: more of this is mentioned below).
do a search on the error you mentioned. there is more help in this forum and you will be able to troubleshoot more informed & you will definately find something. the following paragraphs detail a little more of my own problem and solution. obviously your case will differ but there may be some clue that you can use to find your own resolution.
a: i have used autodesks utility AWS for my inventor's content center / adms / vault management, since i work on a single computer and have no other staff that need to access my projects on a network server. The situation i mention above, i recently was installing some windows components (on a different topic altogether) i installed IIS just to experiment on. Now it was some days before i tried to use the content center once again. to my surprise i could not get access to the content center / vault etc. it was only after reading through forums such as this and remembering my install of IIS that i went back and uninstalled IIS and wham, my content center and vault were once again accessible. windows components are seen through " control panel, add remove programs, Add / remove windows components". (in my case i just had to un-check the IIS box to unload it).
b: trying to reduce the space used on my c drive some year or so ago i compessed some folders. After that i found i could not get into vault / content center so i assumed that in the process i had damaged something, and after much trouble shooting , reninstalling of inventor and vault to no avail, i concluded that i had damaged my microsoft sql resources. after more trials and reinstalls, some weeks later i noticed that there was an entry in "add remove programs" called Microsoft SQL Server 2005. as a last resort i removed this and restarted. perhaps then upon a reinstall of inventor and vault / adms this utility was reinstalled correctly as i do not recall having to install Microsoft SQL Server 2005 after that. this simeple 30 minute process fixed all of my problems.
hope that helps.
-Mark.
best regards,
- Mark
(Kudo or Tag if helpful - in case it also helps others)
PDSU 2020 Windows 10, 64bit.